With the increased use of wireless communication devices, spectrum has become scarce. In many cases, network operators providing services on one particular band have had to provide service on a separate band to accommodate its customers. For example, network operators providing service on a GSM system in a 900 MHz frequency may have to rely on a DCS system at an 1800 MHz frequency. Accordingly, communication devices, such as cellular radio telephones must be able to communication at both frequencies, or even a third system, such as DCS 1900. Such a requirement to operate at two or more frequencies creates a number of problems. For example, the communication device would have increased size and cost if the transmitter included separate components to transmit signals in each bands.
Accordingly, there is a need for a method and apparatus for transmitting communication signals in a plurality of bands while minimizing the increase in components.